test_arbiter.py

# -*- coding: utf-8 -
#
# This file is part of gunicorn released under the MIT license.
# See the NOTICE for more information.

import os

try:
    import unittest.mock as mock
except ImportError:
    import mock

import gunicorn.app.base
import gunicorn.arbiter


class DummyApplication(gunicorn.app.base.BaseApplication):
    """
    Dummy application that has a default configuration.
    """

    def init(self, parser, opts, args):
        """No-op"""

    def load(self):
        """No-op"""

    def load_config(self):
        """No-op"""


@mock.patch('gunicorn.sock.close_sockets')
def test_arbiter_stop_closes_listeners(close_sockets):
    arbiter = gunicorn.arbiter.Arbiter(DummyApplication())
    listener1 = mock.Mock()
    listener2 = mock.Mock()
    listeners = [listener1, listener2]
    arbiter.LISTENERS = listeners
    arbiter.stop()
    close_sockets.assert_called_with(listeners, True)


@mock.patch('gunicorn.sock.close_sockets')
def test_arbiter_stop_child_does_not_unlink_listeners(close_sockets):
    arbiter = gunicorn.arbiter.Arbiter(DummyApplication())
    arbiter.reexec_pid = os.getpid()
    arbiter.stop()
    close_sockets.assert_called_with([], False)


@mock.patch('gunicorn.sock.close_sockets')
def test_arbiter_stop_parent_does_not_unlink_listeners(close_sockets):
    arbiter = gunicorn.arbiter.Arbiter(DummyApplication())
    arbiter.master_pid = os.getppid()
    arbiter.stop()
    close_sockets.assert_called_with([], False)


@mock.patch('gunicorn.sock.close_sockets')
def test_arbiter_stop_does_not_unlink_systemd_listeners(close_sockets):
    arbiter = gunicorn.arbiter.Arbiter(DummyApplication())
    arbiter.systemd = True
    arbiter.stop()
    close_sockets.assert_called_with([], False)


@mock.patch('os.getpid')
@mock.patch('os.fork')
@mock.patch('os.execvpe')
def test_arbiter_reexec_passing_systemd_sockets(execvpe, fork, getpid):
    arbiter = gunicorn.arbiter.Arbiter(DummyApplication())
    arbiter.LISTENERS = [mock.Mock(), mock.Mock()]
    arbiter.systemd = True
    fork.return_value = 0
    getpid.side_effect = [2, 3]
    arbiter.reexec()
    environ = execvpe.call_args[0][2]
    assert environ['GUNICORN_PID'] == '2'
    assert environ['LISTEN_FDS'] == '2'
    assert environ['LISTEN_PID'] == '3'


@mock.patch('os.getpid')
@mock.patch('os.fork')
@mock.patch('os.execvpe')
def test_arbiter_reexec_passing_gunicorn_sockets(execvpe, fork, getpid):
    arbiter = gunicorn.arbiter.Arbiter(DummyApplication())
    listener1 = mock.Mock()
    listener2 = mock.Mock()
    listener1.fileno.return_value = 4
    listener2.fileno.return_value = 5
    arbiter.LISTENERS = [listener1, listener2]
    fork.return_value = 0
    getpid.side_effect = [2, 3]
    arbiter.reexec()
    environ = execvpe.call_args[0][2]
    assert environ['GUNICORN_FD'] == '4,5'
    assert environ['GUNICORN_PID'] == '2'


@mock.patch('os.fork')
def test_arbiter_reexec_limit_parent(fork):
    arbiter = gunicorn.arbiter.Arbiter(DummyApplication())
    arbiter.reexec_pid = ~os.getpid()
    arbiter.reexec()
    assert fork.called is False, "should not fork when there is already a child"


@mock.patch('os.fork')
def test_arbiter_reexec_limit_child(fork):
    arbiter = gunicorn.arbiter.Arbiter(DummyApplication())
    arbiter.master_pid = ~os.getpid()
    arbiter.reexec()
    assert fork.called is False, "should not fork when arbiter is a child"


@mock.patch('os.fork')
def test_arbiter_calls_worker_exit(mock_os_fork):
    mock_os_fork.return_value = 0

    arbiter = gunicorn.arbiter.Arbiter(DummyApplication())
    arbiter.cfg.settings['worker_exit'] = mock.Mock()
    arbiter.pid = None
    mock_worker = mock.Mock()
    arbiter.worker_class = mock.Mock(return_value=mock_worker)
    try:
        arbiter.spawn_worker()
    except SystemExit:
        pass
    arbiter.cfg.worker_exit.assert_called_with(arbiter, mock_worker)


@mock.patch('os.fork')
def test_arbiter_logs_worker_exit_errors(mock_os_fork):
    mock_os_fork.return_value = 0

    error = ValueError('testing')
    class WorkerExit(object):
        @staticmethod
        def worker_exit(arbiter, worker):
            raise error

        def get(self):
            return self.worker_exit

    arbiter = gunicorn.arbiter.Arbiter(DummyApplication())
    arbiter.cfg.settings['worker_exit'] = WorkerExit()
    arbiter.pid = None
    mock_worker = mock.Mock()
    arbiter.worker_class = mock.Mock(return_value=mock_worker)
    arbiter.log = mock.Mock()
    try:
        arbiter.spawn_worker()
    except SystemExit:
        pass
    arbiter.log.warning.assert_called_with(
        'Exception during worker exit', exc_info=error)


@mock.patch('os.waitpid')
def test_arbiter_reap_workers(mock_os_waitpid):
    mock_os_waitpid.side_effect = [(42, 0), (0, 0)]
    arbiter = gunicorn.arbiter.Arbiter(DummyApplication())
    arbiter.cfg.settings['child_exit'] = mock.Mock()
    mock_worker = mock.Mock()
    arbiter.WORKERS = {42: mock_worker}
    arbiter.reap_workers()
    mock_worker.tmp.close.assert_called_with()
    arbiter.cfg.child_exit.assert_called_with(arbiter, mock_worker)


class PreloadedAppWithEnvSettings(DummyApplication):
    """
    Simple application that makes use of the 'preload' feature to
    start the application before spawning worker processes and sets
    environmental variable configuration settings.
    """

    def load_config(self):
        """Set the 'preload_app' and 'raw_env' settings in order to verify their
        interaction below.
        """
        self.cfg.set('raw_env', [
            'SOME_PATH=/tmp/something', 'OTHER_PATH=/tmp/something/else'])
        self.cfg.set('preload_app', True)

    def wsgi(self):
        """Assert that the expected environmental variables are set when
        the main entry point of this application is called as part of a
        'preloaded' application.
        """
        verify_env_vars()
        return super(PreloadedAppWithEnvSettings, self).wsgi()


def verify_env_vars():
    assert os.getenv('SOME_PATH') == '/tmp/something'
    assert os.getenv('OTHER_PATH') == '/tmp/something/else'


def test_env_vars_available_during_preload():
    """Ensure that configured environmental variables are set during the
    initial set up of the application (called from the .setup() method of
    the Arbiter) such that they are available during the initial loading
    of the WSGI application.
    """
    # Note that we aren't making any assertions here, they are made in the
    # dummy application object being loaded here instead.
    gunicorn.arbiter.Arbiter(PreloadedAppWithEnvSettings())